Seth Green character Milo (voice)
Joan Cusack character Mom (voice)
Dan Fogler character Gribble (voice)
Breckin Meyer character Alien (voice)
Elisabeth Harnois character Ki (voice)
Tom Everett Scott character Milo's Dad (voice)
Mindy Sterling character Supervisor (voice)
Julene Renee character Martian (voice)
Raymond Ochoa character Martian Hatchling (voice)
Robert Ochoa character Martian Hatchling (voice)
Ryan Ochoa character Martian Hatchling (voice)
Seth Robert Dusky character Milo (voice) (as Seth Dusky)
Amber Gainey Meade character Martian
Dee Bradley Baker character Two Cats (uncredited)
